Abstract: This article reports on a series of empirical studies that assessed continuing claims for the utility of subtest analysis. Large and representative cross-samples were formed from the national standardization samples of the Wechsler Intelligence Scale for Children-Third Edition (Wechsler, 1991), the Wechsler Individual Achievement Test (The Psychological Corporation, 1992), and the Guide to the Assessment of Test Session Behavior (Glutting & Oakland, 1993) (IV = 640) and for the Differential Ability Scales (Elliott, 1990) and the Learning Behaviors Scale (McDermott, Green, Francis, & Stott, 1996) (IV = 1,250). Hierarchical regression and discriminant models were used to determine the maximum potential of ability subtests to explain variation in academic achievement, stylistic classroom learning, and test-session behavior and disposition, and to distinguish among groups of exceptional children. Analyses demonstrated that ipsative subtest scores provide no information beyond that already available through conventional normative subtests. Moreover, even normative subtests add little information to what is known through global ability measures. Implications are drawn for psychological practice.